Stylus-bar mounting for sound boxes



H. J. DURBOROW. STYLUS BAR MOUNTING FOR SOUND BOXES.

APPLICATION FILED DEC. 16, i920.

Patented. Nov. 28, 1922.

Fatented Nov. 28, 1922 s'rars HARRY J. DURBOROYV, OF PHILADELPHIA, PENNSYLVANIA.

STYLUS-BAR rlrounrrne, non sounn Bonus.

A pplicati on filed December 16, 1920, Serial 1%. 431,068.

T 0 all w from it may concern Be it known that I, HARRY J. DUnBonoW, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Stylus-Bar Mountings for Sound Boxes, of which the following is a specification.

One object of my invention is to provide a mounting for a stylus bar for soundboxes of talking machines which will effect an improved or more accurate reproduction of sound.

Another object is to make such mounting of a construction which can be quickly and easily installed.

A further object is to make my improved mounting of a durable construction and so that it can be quickly and easily manufactured.

These objects, and other advantageous ends which will be described hereinafter, I attain in the following manner, reference being had to the accompanying drawings in whicl i Figure 1 is a front elevation of a sound box including my improved stylus bar mounting,

Figure 2 is an inverted ure 1,

Figure 3 is an enlarged fragmentarysection taken on the line 33 of Figure 1,

Figure t is an enlarged fragmentary sectional elevation taken on the line 4-4 of F igure 2,

plan view of Fig- .Figure 5 is an enlarged front elevation of a spring device which forms a part of my invention,

F igure 6 is a bottom plan view of the device shown in Figure 5, i

Figure 7 is a top plan view of the device shown in Figures 5 and 6, and;

Figure 8 is a plan view of a blank out of which the device shown in Figures 5, 6 and 7 is constructed. I

Referring to the drawings, 9 represents a sound box including a diaphragm 10; the frame 11 of said box having a projection 12 providing two lips 13 which are spaced apart and extend downwardly to provide an intervening space 14. A stylus bar 15 has its upper end secured to the diaphragm and at its lower end is provided with a needle vided thereby which permits a firm connecchuck 16; said needle chuck having a. flat upper surface 17 which 13 located to the rear of the stem portion 18 ofthe stylus bar which'connects with the diaphragm 10.

My invention includes adevic'e 19 which is made from a blank of sheet material, for example from bronze or spring steel; said blank including a central portion. 20 having integrally formed strips 21 and 22 which extend in opposite directions andat a slant to the portion 20 as clearly shown in Figure 8.

The strips 21 and 22 while in the blank may be made substantially parallel to each other or in otherwords are included in parallel planes. These strip'portions 21 and 22 are turned or twisted into a helical formsuch for example asclearly shown in Figures 5 to 7 inclusive and each of the strips21and 22 at their free ends have an enlarged flat portion 23. These portions: 23 are so arranged, that after the stripportions 21 and 22 are twisted in helical form, that theywill he in a straight line'with the central portion 20 and in the "same plane therewith. Figure 5 shows these portions 23 in the same plane with the portion 20 and Figures 6 and 7 show that theseportions 23 are in straight alignment with the portion 20. Thus my improved device is in the form of a helical spring having opposite end portions flat and a central flat portion as clearly obvious from the construction illustrated in the drawing.

The central portion 20 is preferably provided with two holes 24,- and the end portions 23 are preferably provided witha hole 25. Screws 26 extend through the holes 2 1 and secure the portion 20 to the surface 17 of the needlechuck 1,6. While other screws 27 secure the end port-ions 23 to the under surfaces of the lips 13 and in this manner the stylus bar is resiliently connected to the frame of the sound box, I may in some instances insert cores 28 within the turns or helical portions 29 of the device 19 and these cores as illustrated are made of cork and serve to kill or stop any vibrations imparted to the device which might otherwise tend to deflect sound directly from the device instead of transmitting the vibrations through the stem 18 of the stylus bar to the diaphragm 10.

A stylus bar mounting such as above de scribed, can be quickly and easily made and installed and has been found to give exceptionally good results. if mounting is protion but a resilient connection since the de vice can permit a certain yielding movement of the stylus bar in either direction Within the length of the device and also a torsional or turning movement which serves to keep the parts central during'use.

\Vhile I have described my invention as taking a particular form, it will be under-' stood that the various parts of my invention may be changed without departing from the spirit thereof,and hence I do not limit myself to the precise construction set forth, but consider that I am at liberty to make such changes and alterations as fairly come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:---

1. The combination of a member having a helically twisted portion and other portions out of axial alignment. with said twisted portion; a diaphragm case; a stylus bar; and means for securing said secondanentioned portions of said member respectively to the diaphragm case and stylus bar; substantially is described.

2. A device for securing a stylus bar to a sound box, including a member having a helically twisted portion and other portions for respective connection with the stylus bar and a part of the sound box; and a core member positioned within and in engagement with the convolutions of said helically twisted portion of the member; substantially as described. y

3. The combination of a member including helically twisted portions spaced apart and connected by a. flat portion said member having other flat portions formed therein, the arrangement being such that said helically twisted portions are respectively between said latter flat portions and said first flat portion; a diaphragm casehaving flat surface portions; a stylus bar having a flat surface portion; means for securing said second flat portions of the member in coinciding engagement with said flat surface portions of the case; and means for securing said first mentioned fiat surface of the member to the flat surface portion of the stylus bar; substantially as described.

4:. The combination of a member including helically twisted portions spaced apart and connected by a flat portion, said member having other flat portions formed therein, the arrangement being such that said helically twisted portions are respectively between said latter fiat portions and said first flat portion; a diaphragm case having flat surface portions; a stylus bar having a flat surface portion; means for securing said second flat portions of the member in coinciding engagementwith said flat suri' ace portions of the case; and means for securing said first mentioned flat surface of the member to the flat surface portion of the stylus bar, said fiat portions of said member all being normally included in the same plane; substantially as described.

5. The combination of amember having a helically twisted portion and otherportions between which said twisted portion is lo cated, said other portions being out of alignment with the helical curvature of said twist ed portion; a diaphragm case; a stylus bar; and means for securing said second mentioned portions respectively to said case and stylus bar; substantially as described.

6. The combination of diaphragm case; a. stylus bar and a member having a helically twisted part and other portions; and means for insuring the securing of said latter portions of the member to the case and bar in adefinite predetermined position; substan tially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HARRY J. DURBOROW 

